Figure 1
From: Robust methods for population stratification in genome wide association studies
The orthogonal distance versus the score distance for one simulated dataset. The plot is based on projection pursuit robust PCA using the GRID algorithm for one simulated dataset under scenario S4 in simulation II. The vertical line is the outlier cutoff line for the score distance, the horizontal line is the outlier cutoff for the orthogonal distance, and those points on the right of the vertical line or above the horizontal line were identified as outliers.